Measures for determining the quality of bearing installation

Writer： admin Time：2025-11-25

After the installation of the bearing in the host, if the radial runout of the main shaft is measured, it can be found that there is a certain change in the measured value for each rotation; When measuring continuously, it can be observed that after a certain number of rotations, this change will approximately repeat itself. The indicator for measuring the degree of change is the cyclic rotation accuracy. The number of revolutions required to approximately repeat the change represents the "quasi period"of cyclic rotation accuracy. If the magnitude of the change within the quasi period is large, it is called poor cyclic rotation accuracy.

If appropriate preload is applied to the spindle and the speed is gradually reduced to near the required speed to achieve the "running in"effect of the bearings, the cyclic rotation accuracy of the spindle can be improved The main factors used for adjustment are installation, use and maintenance, upkeep and repair, etc. that meet technical requirements. According to the technical requirements for bearing installation, use, maintenance, and upkeep, the contact load, speed, temperature, vibration, noise, and lubrication status of the bearings should be monitored and inspected. If any abnormalities are found, the cause should be immediately identified and adjusted to restore normal operation. Installation conditions are one of the factors that affect the use of bearings and are often the primary cause of incorrect installation of load-bearing capacity between different parts of the package. In abnormal operating conditions and premature termination of life, contact fatigue failure occurs Contact fatigue failure refers to the failure of the working surface of a bearing under alternating stress. Contact fatigue peeling occurs on the working surface of bearings, often accompanied by fatigue cracks. It first occurs at the location of large alternating shear stress below the contact surface, and then extends to the surface to form different peeling shapes, such as pitting or pitting peeling, and peeling into small flakes is called shallow peeling. Due to the gradual expansion of the peeling surface, it often extends to deeper layers, forming deep peeling. Deep peeling is the fatigue source of contact fatigue failure.

2. Wear and tear failure Wear failure refers to the failure caused by the continuous wear of the working surface metal due to the relative sliding friction between surfaces.

Continuous wear will cause gradual damage to bearing components, ultimately leading to loss of bearing dimensional accuracy and other related issues.

Wear and tear may affect shape changes, increase clearance, and alter the morphology of the working surface, which may affect the lubricant or contaminate it to a certain extent, resulting in complete loss of lubrication function, thus causing the bearing to lose rotational accuracy and even malfunction. Wear and tear failure is one of the common failure modes of various types of bearings, which can usually be divided into abrasive wear and adhesive wear according to the form of wear.

1) Instrument testing Using methods such as ferrography, SPM, or the new VIB05 detector to assess the operational status of bearings and determine whether maintenance or replacement is necessary is a convenient and reliable approach.

For example, when using the VIBO5 detector, which is a newly designed machine condition detection instrument based on a microprocessor, it has vibration detection, bearing condition analysis, and infrared temperature measurement functions. It is easy to operate, automatically indicates status alarms, and is very suitable for on-site equipment operation and maintenance personnel to detect equipment status, timely discover problems, and ensure the normal and reliable operation of equipment.

By using such instruments, the working potential of bearings can be fully utilized, bearings can be repaired in a timely manner, and faults can be avoided. It is more suitable for young workers to make up for their lack of experience.

2) Manual testing In places where the above-mentioned instruments are not available, monitoring tools modified from medical stethoscopes can be used for testing Experienced operators can also use tools such as round bars or wrenches to resist the machine housing parts closer to the bearings, and use their ears to monitor the running sound of the bearings through the tools.

Normal bearing operation sound should be uniform, smooth, and not harsh, while abnormal bearing operation sound is intermittent, impactful, or harsh.